EVERETT, Wash. (AP) _ A teen-age boy admitted he fatally beat and then raped a 12-year-old baby sitter over the weekend because he reportedly hopes to one day get out of prison.

``It was his idea'' to plead guilty, his mother, Sharon Dodge, told the Seattle Post-Intelligencer. ``He wanted to get out (of prison) some day. He may be 50 or 60 years old, but he would still be out.''

David Dodge, 17, stunned friends and prosecutors Wednesday by pleading guilty as an adult to first-degree murder, rape and burglary charges in the weekend death of Ashley Jones. Prosecutors said they will ask for the maximum penalty, life in prison, when he is sentenced Nov. 3.

Friends agreed Dodge had problems _ multiple juvenile convictions for burglary _ but no reputation for violence.

``He did it, but it's not the David I know,'' said Kelli Clark, 15, expressing the sentiments of many Camano Island teens at his arraignment. ``Everybody knew him. He was a good guy, but he's got a bad side.''

``I would never have thought in the worst day of my whole life that he could be capable of it,'' said another friend, Jeff Hoffman, 18.

Ashley was watching five young children Saturday night at a neighbor's house in Stanwood, about 40 miles north of Seattle.

Dodge entered through an unlocked door, bludgeoned the girl with a piece of wood and raped her while she was unconscious, prosecutors said.

The parents of the younger children returned early Sunday and found Ashley's badly beaten body. She died later Sunday at a Seattle hospital. Her young charges, ages 2 to 8, slept through the attack and were unharmed.